Optimized Design And Application Of Multi-layer Plate Low-Frequency Magnetic Shielding

With the continuous improvement of the voltage level,intelligence degree and the electronic degree of the power system,on the one hand,the electromagnetic environment generated by the power transmission and transformation equipment is more complex,on the other hand,the types and quantity of secondary equipment are more and more.Especially under the background of high fusion of primary and secondary equipment,the potential danger of electromagnetic interference of secondary equipment is increasing.Low-frequency magnetic field shielding is widely used in electric power engineering.The problem of shielding the circular coil is a classical problem in magnetic shielding.Based on the effect of the material,the thickness allocation,the receiving distance,the radius of the layer.For the common case of double plate,the calculation formula is simplified,and the calculation of "large numbers" is avoided.The results are verified by experiments and finite element simulations./The results show that the difference between layers and the increase of the layer space,and the number of layers has a saturation effect on the shielding efficiency.The calculation results under the parameter configuration of the shielding efficiency test standard of the shielding chamber show that the shielding performance increment of 1mm with a total thickness of 1mm and 0.1 mm is about OdB/OdB(50Hz),12dB/2dB(1 kHz),30dB/7dB(10 kHz),43dB/26dB(100 kHz).These results indicate that the use of layered structure can significantly reduce the thickness of single layer materials,so that flexible shielding materials with good conformation,such as aluminum foil and copper foil,can be used.This paper provides ideas for the optimal design and application of multi-layer plate low-frequency magnetic shielding.At the end of the article,the research content is summarized and put forward.